Jackson donated money to the school, and the auditorium was named for him in 1989.
Later, Jackson's name was covered up with boards due to the child molestation scandal in 2003.
He was never convicted, and following his death, an online campaign began to restore his name to the auditorium.
School district Superintendant Ramon Cortines directed the cover to be removed "in recognition of Michael Jackson's musical legacy and contribution to modern culture."
It was finally put on display again on Friday.
The Associated Press contributed to this report.